As is well known in the art, different kinds of light bulbs have been developed in addition to the familiar incandescent light bulb, such as halogen lights, florescent lights and LED (light emitting diode) lights. Halogen lights have some disadvantages, such as high temperatures and relatively high wattage.
LED light bulbs have several advantages. For example, white LEDs have been developed that will last up to 50,000 hours, about 50 times as long as a 60-watt bulb. LED light bulbs are advantageous in places where changing bulbs is difficult or expensive (e.g., hard to reach places, such as the exterior of buildings). Hotels may use LEDs to save costs of replacing burned-out incandescent bulbs.
Although a LED requires minute amounts of electricity, generates little heat, and transmits a focused beam of light, there is a recognized problem of gathering enough light so that the LED light can compete with an incandescent, halogen or even a florescent light.
The prior art has recognized the need for focusing light from LEDs to solve the above problem. For example, some LED light bulbs place the LED in a cup shaped mirrored cavity to focus and intensify the light. U.S. Pat. No. 6,840,654 to Guerrieri, et al. describes an LED light bulb with a conical reflecting chamber and a rear housing to accommodate a series of light emitting diodes, each diode residing in a chamber adapted therefore.
U.S. Pat. No. 6,361,190 to McDermott describes a large surface LED lighting device using a single reflecting means to increase the divergence of light.
PCT published patent application WO 02/14738A1 to Ming describes a combination of a reflector and magnifying lens to increase the brightness and utility of an LED light.
US Patent Application US2002/0080622 to Pashley et al describes a multifaceted cup assembly to increase the divergence and intensity of an LED light.